Mechanical Locking of Floor Panels with Vertical Snap Folding

1. A set of essentially identical floor panels, each floor panel comprising long and short edges provided with a mechanical locking system comprising first and second connectors integrated with the floor panels, and wherein immediately juxtaposed upper parts of two adjacent joint edges of two joined floor panels together define a vertical plane perpendicular to the main plane of the panels, the first connector comprises a locking strip with an upwardly directed locking element, at a first edge of a floor panel, configured to cooperate with a downwardly open locking groove at an adjacent second edge of another floor panel for connecting the adjacent edges in a horizontal direction perpendicular to the vertical plane, the second connector comprises a tongue, either at the first or at the second edge, extending horizontally perpendicular to the vertical plane, configured to cooperate with a horizontally open tongue groove at the other of said first or second edge for connecting the adjacent edges in a vertical direction parallel to the vertical plane, the connectors at the long edges are configured to be locked with angling and the connectors at the short edges are configured to be locked with vertical snap folding, whereby a long edge of a new panel in a second row is configured to be connected to a long edge of a first panel in a first row by angling, whereby a second short edge of the new panel and a first short edge of a second panel in the second row are configured to be connected with vertical snap folding motion, wherein the tongue at one of the short edges is formed in one piece with the corresponding panel and protrudes from a substantially vertical upper surface at said one short edge, wherein the locking strip at the short edges is bendable, to obtain a resilient bending during the vertical snap folding action, which bending facilitates the assembling of the tongue and the tongue groove, and wherein the first and the second connector at the short edges are configured to overcome friction between connectors on the long edges, facilitating a displacement, by a spring back force from the bending of the short edge locking strip, of the new panel in the horizontal direction along the long edge during the vertical snap folding action so that the connectors on the short edges are pulled together automatically to be in a locked position without a sideward pressure on the new panel from an external force.

2. The set of floor panels as claimed in claim 1 , wherein the tongue at the short edges is rigid such that the tongue protrudes outside the upper vertical surface during the whole vertical snap folding action.

3. The set of floor panels as claimed in claim 1 , wherein the tongue at the short edges comprises a material of wood fibres.

4. The set of floor panels as claimed in claim 1 , wherein the panels have a thickness and wherein the tongue on the short edge extends a tongue distance from the vertical plane which tongue distance is at least 0.1 time the floor thickness.

5. The set of floor panels as claimed in claim 1 , wherein the tongue and the tongue groove on the short edges have upper contact surfaces, which are essentially planar and horizontal.

6. The set of floor panels as claimed in claim 1 , wherein the locking element on the short edge has an guiding surface at an upper part and a locking surface below and adjacent to the guiding surface and wherein the locking groove on the short edges has a guiding surface on the lower part under and adjacent to a locking surface, wherein the locking surfaces are configured to cooperate to prevent separation of the panels in the horizontal direction and the guiding surfaces are configured to cooperate to guide the locking element into the locking groove during the vertical snap folding.

7. The set of floor panels as claimed in claim 6 , wherein the horizontal extension of locking surfaces and guiding surfaces of the locking element and the locking groove at the short edges is equal or larger than the tongue distance.

8. The set of floor panels as claimed in claim 1 , wherein the short edge strip comprises three parts, an inner groove part located between the inner part of the tongue groove and the vertical plane , an outer locking part located between the outer part of the strip and a vertical locking plane that intersects a locking surface of the locking element, and an intermediate flexible part located between the inner groove part and the outer locking part wherein a lower part of the strip extends at least over a part of the intermediate part and above the rear face of the panel.

9. The set of floor panels as claimed in claim 1 , wherein a cross section of the locking system on the long edges is configured such that all operative surfaces that in a locked position are in contact with each other are such that they extend over a total length, which is less than the floor thickness, in order to reduce the friction.

10. The set of floor panels as claimed in claim 1 , wherein the short edge with the tongue groove is provided with a second tongue above the tongue groove, which second tongue protrudes horizontally.

11. The set of floor panels as claimed in claim 1 , wherein an upper surface of the tongue is parallel to a locking surface of the locking groove.

12. A set of essentially identical floor panels each comprising long and short edges provided with a mechanical locking system comprising first and second connectors integrated with the floor panels, and wherein immediately juxtaposed upper parts of two adjacent joint edges of two joined floor panels together define a vertical plane perpendicular to the main plane of the panels, the first connector comprises a locking strip with an upwardly directed locking element, at a first edge of a floor panel, configured to cooperate with a downwardly open locking groove at an adjacent second edge of another floor panel for connecting the adjacent edges horizontally in a direction perpendicular to the vertical plane, the second connector comprises a tongue, either at the first or the second edge, extending horizontally perpendicular to vertical plane, configured to cooperate with a horizontally open tongue groove, at the other of said first or second edge, for connecting the adjacent edges in vertical direction parallel to the vertical plane, the connectors at the long edges are configured to be locked with angling and the connectors at the short edge are configured to be locked with vertical snap folding, wherein the tongue at one of the short edges is formed in one piece with the panel and configured to protrude from a substantially vertical upper surface at the short edge with the tongue, and wherein the mechanical locking system at the long edges is configured such that a new panel is displaceable vertically substantially along the vertical plane of a first panel and relative the first panel when the new floor panel is in an angled position in relation to the first floor panel and with the tongue within the tongue groove, and the upper part of the locking element within the locking groove.

13. The set of essentially identical floor panels as claimed in claim 12 , wherein an upper surface of the tongue is substantially parallel to a locking surface of the locking groove.

14. The set of essentially identical floor panels as claimed in claim 12 , wherein the angle of the upper surface of the tongue and the locking surface of the locking groove against the horizontal plane is more than about 60 degrees.

15. The set of essentially identical floor panels as claimed in claim 14 , wherein the angle is more than about 70 degrees.

16. The set of floor panels as claimed in claim 12 , wherein the short edge with the tongue groove is provided with a second tongue above the tongue groove, which tongue protrudes horizontally.

17. A set of essentially identical floor panels each comprising long and short edges, whereby the short edges are provided with a mechanical locking system comprising first and second connectors integrated with the floor panels, the first connector comprises a locking strip with an upwardly directed locking element, at a first short edge of a floor panel, configured to cooperate with a downwardly open locking groove at an adjacent second short edge of another floor panel for connecting the adjacent edges horizontally, the second connector comprises a tongue, either at the first or the second short edge, extending horizontally, configured to cooperate with a horizontally open tongue groove, at the other of said first or second short edges, for connecting the adjacent edges in vertical direction configured to be locked with a vertical motion, wherein the tongue at one of the short edges is formed in one piece with the panel and configured to protrude from a substantially vertical upper surface at the short edge with the tongue, wherein an upper surface of the tongue is substantially parallel to a locking surface of the locking groove wherein the angle of the upper surface of the tongue and the locking surface of the locking groove against the horizontal plane is more than about 50 degrees, and wherein the short edge with the tongue groove is provided with a second tongue above the tongue groove, which second tongue is formed of the same material as the core of the floor panel, extends down to the tongue groove, and protrudes horizontally.

18. The set of essentially identical floor panels as claimed in claim 17 , wherein the angle is more than about 60 degrees.